Polyolefins such as high density polyethylene (HDPE) homopolymer and copolymer can be produced using various combinations of catalyst systems and polymerization processes. Chromium-based catalyst systems can, for example, produce olefin polymers having good extrusion processibility and polymer melt strength, typically due to their broad molecular weight distribution (MWD).
In some end-use applications, such as blow molding, it can be beneficial to have the processibility, die swell, and melt strength similar to that of an ethylene polymer produced from a chromium-based catalyst system, as well as improvements in toughness, topload strength, and environmental stress crack resistance (ESCR) at equivalent or higher polymer densities. Accordingly, it is to these ends that the present invention is directed.